Coil stabilising system

ABSTRACT

An apparatus for supporting a coil of strip material and for rotating it about its polar axis comprises two sets of rollers arranged in parallel side-by-side relation, each set of rollers being coaxial upon a shaft. One driven roller is provided to rotate the coil by frictional engagement therewith, the remaining said rollers being idlers whose peripheral speed is permitted to vary compared to that of the driven roller to accommodate local variations in the peripheral speed of the coil which may arise due to local variations in coil radius. The width of the coil contacting surface of each roller constitutes a minor portion only of the axial distance spanning the said surfaces of the two rollers axially most distant from each other.

United States Patent [191 Reed I Sept. 10, 1974' COIL STABILISING SYSTEM 3,154,263 10/1964 Fischer 242/66 x Inventor: Geoffrey Ronald Reed, 3,692,252 9/1972 Perconti 242/65 England Primary Examiner-John W. Huckert [73] Assignee: British Steel Corporation, London, Assistant Examiner-Edward J. McCarthy England [22] Filed: June 4, 1973 [21] Appl. No.: 366,291

[30] Foreign Application Priority Data June 5, 1972 Great Britain 26090/72 [52] US. Cl. 242/65,242/78.7 [51] Int. Cl B65h 17/08 [58] Field of Search 242/78.7, 78.1, 65, 66,

[56] References Cited 1 UNITED STATES PATENTS 2,267,161 12/1941 Miller 242/78.7 2,345,373 3/1944 Ayers 242/78.7 2,760,544 8/1956 Lorig 242/78.7 X

Attorney, Agent, or Firm-Bacon & Thomas [5 7] ABSTRACT An apparatus for supporting a coil of strip material and for rotating it about its polar axis comprises two sets of rollers arranged in parallel side-by-side rela tion, each set of rollers being coaxial upon a shaft. One driven roller is provided to rotate the coil by frictional engagement therewith, the remaining said rollers being idlers whose peripheral speed is permitted to vary compared to that of the driven roller to accommodate local variations in the peripheral speed of the coil which may arise due to local variations in coil radius. The width of the coil contacting surface of each roller constitutes a minor portion only of the axial distance spanning the said surfaces of the two rollers axially most distant from each other.

7 Claims, 7 Drawing Figures PATENTED SEP 1 DISH SHEET 3 [IF 3 FIG] This invention relates to apparatus for supporting and rotating about its polar axis an object of circular cross section the radius of which varies along its polar axis. An example of such an object is a coil of strip material. The invention is particularly but not exclusively applicable to apparatus for supporting and rotating coils of metal strip which are to be packaged.

In order to package a coil of metal strip for example in a length of scrap strip, or as described in US. Pat. No. 3,670,877 it is necessary to rotate the coil about its polar axis. We have found that if the coil is merely supported on a pair of parallel driven rolls of about the same length as the axial length of the coil, the coil will tend to move axially along the rolls. This can cause the wrapping sheets on the outer diameter of the coil to skew and thus disrupt the packaging.

We believe this axial movement of the coil is caused by the coil not being perfectly cylindrical. The deviation of the coil from a perfect cylinder is due to the strip not being perfectly rectangular in profile. For example, if the strip tapers slightly from one edge to the other than the coil will be conical due to the accumulation of the difference in thickness across the strip as the coil is wound.

Because the coil is not cylindrical, it does not ride properly on the two rolls. Instead there is some slip between the rollers and parts of the coil, due to its variation in radius from one end to the other, and we believe this results in the undesirable axial movement of the coil.

The present invention can be used to provide a solution to this problem, although it is to be understood that the invention is not limited necessarily to apparatus in which this problem occurs and/or is solved.

According to the invention, there is provided an apparatus for supporting a coil of strip material and for rotating it about its polar axis, comprising a plurality of idler rollers adapted to support the coil and at least one driven roller adapted to rotatethe coil by frictional engagement therewith, said rollers being spaced from each other to contact the periphery of the coil at intervals along its axial extent; the width of the coil contacting surface of each said roller constituting a minor portion only of the axial distance spanning the said surfaces of the said two rollers axially most distant from each other; the arrangement being such that, in operation, the coil is rotated in rolling contact with said idler rollers, the peripheral speed of each said idler roller being permitted to vary compared to that of said driven roller to accomodate local variations in the peripheral speed of the coil.

The term roller used herein of course includes a wheel of small axial length compared to its diameter.

The one or more driven rollers may be arranged also to support the coil.

By supporting the coil on idler rollers which can adjust their peripheral speeds as required to match variations in that of the coil, there is less likelihood of slip between the coil and the rollers. This is especially so because the variation of the radius of the portion of the coil in contact with any one roller is likely to be very small compared to the variation over the axial length of coil spanning the two axially most distant rollers.

Preferably the width of the coil contacting surface of each roller is less than one third of the axial distance spanning the two axially most distant rollers. The said width may with advantage be less than one fifth of the said distance, or even less than one eighth or one tenth.

The width of the coil-contacting surface of each supporting roller ultimately is limited by the permissibile contact pressure on the coil surface. For example, a coil of metal strip may be marked by excessive contact pressure.

The driven roller may be arranged coaxially with one or more said idler rollers, the driven roller being slightly larger in diameter than the idler roller(s).

In a preferred embodiment, further said idler rollers are arranged coaxially with each other, said rollers being disposed parallel to and sideby-side with the aforementioned coaxial rollers.

There may be means for tilting the rotating coil to oppose movement of the object axially of itself.

The means for tilting may comprise means for increasing the effective radius of the coil-contacting surface of one or more of said idler rollers.

Thus, one or more idler rollers may be pivotally mounted and shaped such that said axial movement of the coil tilts the roller and increases its said effective radius.

The said roller may be pivotally mounted on a spherical bearing.

Pivotally mounted idler rollers may be disposed on opposite sides of a said driven roller so that axial movement of the coil in either direction is opposed.

The coil-contacting surface of the at least one driven roller may be of a material (e.g. rubber) adapted to improve frictional engagement of the roller with the coil surface.

The invention will be described merely by way of example with reference to the accompanying drawings, wherein:

FIGS. 1 and 2 are an elevation and plan of apparatus according to one embodiment of the invention;

FIG. 3 is an enlarged sectional view of part of the apparatus of FIG. 1;

FIGS. 4 and 5 are an elevation and plan of apparatus according to another embodiment of the invention;

FIG. 6 is an enlarged sectional view of part of the apparatus of FIG. 4, and I FIG. 7 is a plan view of apparatus according to a further embodiment of the invention.

Referring to FIGS. 1 and 2, a coil of steel strip, partially shown at 10, is supported upon two parallel sets of coaxial rollers 12, 14. The set of rollers 12 comprises a driven roller 16 and two idler rollers 18, 20. The rollers are supported upon a live shaft 22, which in turn is carried in trunnions 24. The driven roller 16 is fixedly mounted on the shaft 22 whereas the idler rollers 18, 20 are rotatably mounted on the shaft as shown in FIG. 3.

From FIG. 3, it can be seen that a sleeve 26 having a facing 28 of polytetra fluoroethylene is carried on the shaft 22, and the roller 18 is rotatably mounted on the sleeve. The roller 18 has an inner facing 30 of polytetra fluoroethylene. The idler roller 20 is similarly mounted.

The live shaft 22 is driven by an electric motor 32 via gearing 33, 34. The roller 16 has a facing of a highfriction material such as rubber and is slightly larger in diameter than the rollers 18, 20.

The construction and mountings of the set of rollers 14 is exactly the same as that of the set 12, except that the shaft 35 and the middle roller 36 are not driven. The roller 36 does not have a rubber facing, and is effectively an idler roller.

In operation, the coil 10 is cradled on the six rollers 16, 18, 20, 36, 38, 40 and bears most heavily on the driven roller 16 due to its slightly larger diameter. When the roller 16 is rotated, its rubber facing frictionally engages the coil and rotates it about its polar axis. The coil rolls upon the five idler rollers, each idler roller adapting a peripheral speed appropriate to the peripheral speed of the portion of coil with which it is in contact.

It will be noted that all the rollers have coil contacting surfaces which are relatively narrow compared to the overall distance 42 spanning the most distant rollers 18 and 20 or 38 and 40. This avoids slip or scrubbing between the coil and the rollers which may occur due to variations in the radius of the coil over a wide roller. The coil contacting surfaces of the rollers 16, 36 are rather less than one fifth of the distance 42 and the widths of the corresponding surfaces of the rollers 18, 20, 38, 40 each are rather less than one twelfth of the distance 42.

Wider rollers than those illustrated can be used subject to the limitation that no single one has a coil contacting surface exceeding a minor portion of the distance 42. That is to say the width of each coilcontacting surface must be less than one half of the distance 42. i

The embodiment of the invention shown in FIGS. 4 and has a majority of parts identical with those in FIGS. 1 and 2. These parts carry the same reference numerals as before. Modified parts carry primed reference numerals.

In this embodiment of the invention, the shafts 22, 35 are not rotatably mounted, but are merely supported in suitable blocks 24. The driven roller 16' and the gear wheel 34 are fixedly mounted on a sleeve 44 which is rotatably mounted on the shaft 22. The idler roller 36 is similarly mounted on the shaft 35'.

The idler rollers 18, 20 each are conical in shape and have their larger ends facing inwards towards each other. The rollers 38, 40' are identical to the rollers 18, 20. The rollers 20, 40' are mounted on their shafts by an arrangement as shown in FIG. 6. The rollers 18, 38 are mounted by a similar arrangement reversed left to right.

In FIG. 6, the roller 20' is supported on the outer race 46 of a spherical bearing, the centre of the spherical bearing surface being on the polar axis of the shaft 22. The race 46 and the roller 20 are free to tilt (clockwise as shown in the figure) about the centre of the spherical bearing against the action of a spring 48 which biases them towards a fixed abutment 50 having 21 facing 52 of anti-friction bearing material. The abutment 50 does not extend below the centre of the spherical bearing, so that tilting of the outer race 46 is not impeded.

In operation, if the coil should drift axially to the right as seen in FIG. 6, then it will tend to tilt the rollers 40 clockwise as shown ghosted in FIG. 6. Because of the conical shape of the rollers 20, 40, the tilting results in a larger radius portion of the roller surfaces contacting the coil, which is consequently tilted as shown at 10. This tilt encourages the coil to return leftwards to its correct axial location on the rollers. If the coil drifts excessively leftwards, the rollers I8, 38' tilt in the opposite sense to the rollers 20, 40' to return the coil to its correct position. The coil is thus effectively centred.

FIG. 7 shows an embodiment of the invention which can accomodate coils of different widths. The apparatus is identical to that of FIG. 1 except that additional idler rollers 50, 52, 54, 56 are provided. The span between the rollers 50, 54, and 52, 56 is less than between the rollers 18, 38 and 20, 40 so narrower coils can be .accomodated. The width of the coil contacting surfaces of the rollers 16, 36 is rather less than one third of the distance spanning the rollers 50 and 52 or 54 and 56. The widths of the surfaces of the rollers 50, 52, 54, 56 are rather less than one tenth of that distance.

If necessary, more than one driven roller can be provided, but it is advisable that the driven rollers are driven at the same peripheral speed and that they contact the same peripheral portion of the coil, or alternatively closely adjacent peripheral portions, in order to avoid the previously mentioned slip or scrubbing. For example, the roller 36 in any of the embodiments can conveniently be driven by the motor 32 at the same speed as the roller 16. The roller 36 should then be rubber faced like the roller 16.

We claim:

1. Apparatus for supporting a coil of strip material and for rotating it about its polar axis, comprising: a plurality of idler rollers adapted to support the coil and at least one driven roller also adapted to support the coil, the driven roller and at least one of said idler rollers being arranged coaxially with each other and said driven roller being of slightly larger diameter than the idler rollers coaxial therewith, said driven roller being adapted to rotate the coil by frictional engagement therewith, said rollers being spaced from each other to contact the periphery of the coil at intervals along its axial extent; the width of the coil-contacting surface of each roller constituting a minor portion only of the axial distance spanning the surface of the two rollers axially most distant from each other; whereby, upon rotation of the coil, the peripheral speed of each said idler roller can vary compared to the speed of said driven roller to accommodate local variations in the peripheral speed of the coil.

2. Apparatus as claimed in claim 1 wherein further idler rollers are arranged coaxially with each other, said further rollers being disposed parallel to and side-byside with the aforementioned said coaxial rollers.

3. Apparatus as claimed in claim 2 comprising means for tilting the rotating coil to oppose movement of the coil axially of itself.

4. Apparatus as claimed in claim 3 wherein the means for tilting comprises means for increasing the effective radius of the coil contacting surface of one or more of said idler rollers.

5. Apparatus as claimed in claim 4 wherein a said idler roller is pivotally mounted and shaped such that said axial movement of the coil tilts the roller and increases its said effective radius.

6. Apparatus as claimed in claim 5 wherein said idler roller is mounted on a spherical bearing.

7. Apparatus as claimed in claim 5 wherein two said pivotally mounted idler rollers are disposed on opposite sides of a said driven roller so that axial movement of the coil in either direction is opposed. 

1. Apparatus for supporting a coil of strip material and for rotating it about its polar axis, comprising: a plurality of idler rollers adapted to support the coil and at least one driven roller also adapted to support the coil, the driven roller and at least one of said idler rollers being arranged coaxially with each other and said driven roller being of slightly larger diameter than the idler rollers coaxial therewith, said driven roller being adapted to rotate the coil by frictional engagement therewith, said rollers being spaced from each other to contact the periphery of the coil at intervals along its axial extent; the width of the coil-contacting surface of each roller constituting a minor portion only of the axial distance spanning the surface of the two rollers axially most distant from each other; whereby, upon rotation of the coil, the peripheral speed of each said idler roller can vary compared to the speed of said driven roller to accommodate local variations in the peripheral speed of the coil.
 2. Apparatus as claimed in claim 1 wherein further idler rollers are arranged coaxially with each other, said further rollers being disposed parallel to and side-by-side with the aforementioned said coaxial rollers.
 3. Apparatus as claimed in claim 2 comprising means for tilting the rotating coil to oppose movement of the coil axially of itself.
 4. Apparatus as claimed in claim 3 wherein the means for tilting comprises means for increasing the effective radius of the coil contacting surface of one or more of said idler rollers.
 5. Apparatus as claimed in claim 4 wherein a said idler roller is pivotally mounted and shaped such that said axial movement of the coil tilts the roller and increases its said effective radius.
 6. Apparatus as claimed in claim 5 wherein said idler roller is mounted on a spherical bearing.
 7. Apparatus as claimed in claim 5 wherein two said pivotally mounted idler rollers are disposed on opposite sides of a said driven roller so that axial movement of the coil in either direction is opposed. 